<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>案例3</title>
</head>

<body id="123" style="text-align: center;">

</body>

</html>
<Script>
    var b = document.querySelector("body")
    b.innerHTML = "右键工具已关闭"
    document.oncontextmenu = function() {
        return false;
    }
</Script>